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ibkoa U; -QQ JUNI Now United States Patent BILLET GRINDER Wallace K. Lowe, Syracuse, N. Y., assignor to Crucible Steel Company of America, Pittsburgh, Pa., a corporation of New Jersey Application December 7, 1953, Serial No. 396,439 16 Claims. (Cl. 51-45) steel billets.

As described in my copending applications Serial Nos. 253,242 filed October 26, 1951, now abandoned, and 279,789 filed April 1, 1952, which issued as Patent No. 2,726,490 on December 13, 1955, both entitled, Billet Grinder, the present application being a continuation-inpart of said applications, rolled or forged steel billets have, in an intermediate stage in their manufacture, relatively rough and uneven surfaces which are made acceptable and surface imperfections which are removed by grinding the surfaces. The grinding apparatus described in the aforesaid pending applications provides means whereby such grinding could be accomplished in a semi-automatic manner, some of the operations being performed without intervention of an operator and other operations required the operation of switches or other devices by an operator.

Although the present invention is useful for grinding material other than billets of steel, it is primarily intended for the automatic grinding of the four surfaces of metal billets which are square in cross-section, such billets being successively loaded and ground as long as an automatic loader associated with the grinding apparatus is supplied with billets and the loading, grinding of the four surfaces and the discharge of a billet after grinding all taking place without the assistance of an operator.

In the grinding apparatus of the present invention as in the apparatus described in the aforesaid copending applications, the grinding wheel which is motor driven is mounted on a pivotally mounted beam. The beam is reciprocaetd by fluid-operated cylinder and piston means, and the pressure of the wheel on thebillet to be ground is controlled by the position of a movable Weight also mounted on the beam, the position of the weight being determined by the current drawn by the wheel driving motor. When desired, the wheel is lifted free from the billet by a further cylinder and piston means. The billet to be ground is mounted on a movable table which is reciprocated at a relatively high rate with respect to the rate of reciprocation of the wheel, the table making several excursions to one excursion of the wheel and being reciprocated along a path extending transversely to the path of reciprocation of the wheel. The billet is clamped on the table by fluid-actuated clamping means and is turned by fluid-actuated turning means so as to present a new face to be ground.

In accordance with the present invention, the operation of the aforesaid apparatus is co-ordina-ted by electrical control apparatus and novel billet loading and discharging apparatus is provided so that, after a billet is loaded on the table by an operator who merely pushes a button to cause such loading, the subsequent operations are automatic. Thus, the billet is clamped in position for grinding, the grinding wheel contacts theiirst face of the and ground,

billet, the reciprocation of the wheel and the table is initiated and the first face is ground a predetermined number of times. When the grinding of the first face is completed, the reciprocation of the wheel and the table is stopped, the wheel is raised from the face of the billet, the billet is unclamped, turned, and reclarnped and the next face of the billet is ground. This cycle is repeated until all of the faces of the billet are ground, at which time the billet is unclamped, the loading and discharging apparatus automatically removes the ground billet from the table and deposits an unground billet on the table. The cycle of operation described above is then automatically initiated so that all the faces of the newly deposited billet are ground. As long as the loading apparatus has a billet thereon, the process continues, but after the last billet on the loading apparatus is deposited the process is stopped until further billets are supplied and/ or an operator intervenes.

By omission of certain features of the invention, the aforesaid process may be interrupted at any desired time. Thus, the process may be stopped each time a billet face is ground or after each billet is ground on all its faces so that further operation of the apparatus is initiated by an operator, but it is to be understood that the pre ferred form of the invention is as described above.

The various objects and advantages of the invention will more fully appear from the following detailed description setting forth the manner in which I now prefer to practice the invention and from the accompanying drawings, in which:

Fig. 1 is a partly diagrammatic plan view of the grinding apparatus of the invention;

Fig. 2 is a front elevation view of a portion of the apparatus shown in Fig. 1 and illustrating said portion in greater detail;

Fig. 3 is a side elevation view of a portion of the grinding apparatus of the invention;

Fig. 4 is a fragmentary, side elevation view of a portion of the grinding apparatus of the invention and is taken from the side of the apparatus opposite from that of Fig. 3;

Fig. 5 is a plan view of a portion of the apparatus shown in Fig. 1 and the apparatus of Fig. 2;

Fig. 6 is an enlarged, fragmentary, plan view of the apparatus shown in Fig. 5;

Fig. 7 is an enlarged, fragmentary, of the apparatus shown in Fig. 5;

Fig. 8 is a fragmentary, cross-sectional view of the apparatus shown in Fig. 5 and is taken along the line d-il indicated in Fig. 5;

Fig. 9 is an enlarged, side elevation view of a portion of the apparatus shown in Fig. 1;

Fig. 10 is an enlarged, front elevation view of the load ing rack shown in Fig. 9;

Fig. 11 is a fragmentary,

front elevation View enlarged perspective view of the loading rack shown in Figs. 9 and 10 and a portion of the grinding table shown in Pig. 9;

Figs. 12 and 13 are fragmentary, cross-sectional views of a portion of the loading rack and the grinding table and are taken along the line 12-12 indicated in Fig. 5

Fig. 14 is an enlarged, fragmentary cross-sectional View of a portion of the grinding table and is taken along the line 14-14 indicated in Fig. 5;

Fig. 15 is a schematic diagram illustrating the system employed in the preferred embodiment of the invention for reciprocating the grinding table and the grinding wheel and for controlling the load on the grinding wheel;

Fig. 16 is a schematic diagram illustrating the system employed in the preferred embodiment of the invention for clamping and turning a billet, for loading and discharging billets and for lifting the grinding wheel; and

Fig. 17 is an electrical circuit diagram showing the circuits which are employed for automatically and manually controlling the grinding apparatus of the invention.

GENERAL DESCRIPTION rotate, but also reciprocates the wheel 11 along a path extending'perpendicular"to the axis ofxrotation of the wheel 11 and raises and lowers'the' wheel 1'1 with respect to a billet 1'2 mountedona reciprocabletablell The table 13 is *reciprocate'd along "a' path "extending transversely to the path of reciprocation 'o'fthewheel '1'1"by apparatus described in *further detail in said copending applications and hereinafter.

Billets areloade'd on the table 13'by'loading apparatus 14 which'also dischargesa ground billet "from the table 13 to a conveyor 15 whichsis driven-by a-motor '16 with its associated drive apparatus 17. Abillet deposited'on the conveyor 15 is moved in a direction away from "the grinding wheel 11 and when it reaches the end of the conveyor 15 the billet operates a-switch'18 which operates a hydraulic valve 19 causing the cylinder and piston means 20 to push the billet from'the conveyor 15 to a conveyor 21 which conveys the ground billet to storage or to further processingequipment.

Grinding wheel operation By reference to Figs. 24,1it will be seenthatthe grinding wheel 11 is mounted on a rotatable shaft 22 which is mounted on apair-of bearings supported on the end of a beam 23. The grinding wheel 11 is rotated with the shaft 22 by a pulley .24 which-is-drivingly connected-by means of belts 25 and a pulley.26-,to an electric motor 27.

The beam 23 is pivotally mounted on a frame 28by means of a shaft 29 which is rotatable in bearings slid-ably mounted on shafts secured'to the .frame 28,.the.details of such mounting not being shown in the drawings of the present application but .beingshown in detail in :the aforesaid copending applications. The motor 27 is secured-to the beam 23 .at a point thereonspac'ed from the pivot shaft 29, and hence the pivot point of' the-beam 23, andiis on the same sideof the shaft 29 as thegrinding whee'l'll.

Due to the fact that the grinding wheel 11 and its associated driving motor .27 are both mounted on the same side of the pivot shaft .29, the weight of these .components tends to press the beam 23 downward-on this side of the shaft 29. A movable counterweight 30 is-rn'ounted on the beam 23 on the oppositesideof the shaft.29 from the wheel 11 and the motor '27. The weight 36 is suspended from the beam 23 by bracketsfil having wheels associated therewith and riding on the beam 23 in the manner described in'the aforesaid ccpending applications.

Counterweight 30 is adjusted along the beam 23 by fluid-actuated cylinder and piston means 32 which is fixedly mounted on the underside .of beam 23. The piston rod 33 of the cylinder and piston means 37. is connected to the counterweight 3t and fluid, such as hydraulic fluid, is admitted into the cylinder and piston means 32 bythe lines 34 and 35 causing the counterweight '30 to move toward and away from the shaft'29.

The beam 23 is 're'ciprocated with respect to' the frame 28 by fluid-actuated cylinder and piston'm'eans '36 which is fixedly secured to theframe ZSQthepiston rod "37 of the cylinder and piston means 36 being connected 'to a bracket 38 secured .to the beam 23.

A quick-operating, air-actuated cylinder and piston means 39 is connected between the-:endof'the beam 23 and the foundation. 40. One'en'd of the means '39 is iii pivotally connected to a bracket 41 secured 'tion 40 and the piston rod 42 of the cylinder and'piston to the foundameans 39 is pivotally connected to a bracket 43 mounted on the end of the beam 23. Air under pressure is supplied to the means 39 through a line 44 and is exhausted from the means 39 through a line 45. When the grinding apparatus is in operation thecylinder and piston means 39 is inoperative in that it exerts substantially no force on the beam 23 and, hence, the pressure applied to the billet v12 .by the .grinding-wheel :11.is determined substantially by the .position of' the counterweight 30. However, in the event that it is desired to lift the grinding wheel ll eitherfrom the billet which is being .gronndonthe table or because the wheel has overrun the billet, then air under pressure is supplied to the rneans39through the line 44 causing the wheel 11 to lift irrespective of the position of the counterweight 30.

Particles removed from the billet being ground .orfrom thegrinding wheel 11 during the grinding process are drawn away .from the machine through an exhaust hood 4-6 connected to an exhaust conduit -47.

Table operation A billet which is to be ground, such as the billet 12, is mounted on the table 13'which is supported on grooved wheels 48 which travel on rails 49, the wheels also being guided by guide rods mounted above'the rails 49 and extending parallel thereto. The rails 49 andiguide rods 50 are mounted on frames 51 and '52 secured to the foundation 40. Fluid-actuated cylinder and piston'means 53 isfixedly secured to theunderside of'the table 13 and, when fluid is admitted to-the opposite ends thereon-the cylinder portion of the cylinder and piston means 53 travel along-the piston rod-54 secured at its'ends to the frames 51 and '52v and carriesthe table 13 with it. Thus, if 'fluid such as hydraulic fluid-is 'snppliedto the cylinder and piston means 53, the table 13 can'be caused to reciprocate along the rails 49.

Billet mounting and clamping The billet '12 is clamped in grinding. position on the top of table .13 by a power-operated clamping-arrangement best showndn Figs..2 and 58. As shownin these figures, the clamping arrangement comprises a pair of double-acting cylinder and piston means 55and 56 having piston rods :57 and 53 extending therefrom. Fluid under pressure and preferably air. is admitted" to the cylinder and piston means 55 and-.Sdthrongh the lines 59- 62 causingthe piston .rods to move in directions determined bytthe line to which the'fluid issupplied. .Arcuatelyslotted members 63' and 64 are attached to .the'ends of the'rods 57 and :58 and engage pins 65 and (id-securedv to :billetengaging members67 and 63having rollers 69 and 70 at their'ends. The billet+engaging members :67 .and68 are pivotally mounted at opposite ends to slidable rend clamps 71 and 72.

The-meanssSSand 56-are mountedon plates 73 and Hand theendclamps 71 and 72am. guided .by the walls of slots .provided'in the plates 73 and 74. The end clamps 71 and 72 are also urged away from the billet 12 by springs 75 and 76 which are connected to the plates 73.and 74by thethreaded bolts77 and 78 and the brackets 79 and 80.

The mounting plates 73 and 74 are adjustable along the top ofthetable 13. The adjusting apparatus for the plate 74 only is shown in detail in Figs. .6 .and 7, but it will be understood that similar apparatus isprovided for the other mounting plate 73. In Figs. 6 and 7 the plate 74 is adjustable by the screw 81 rotatable inthesbearing 82 secured'to the top ofltable'13 andin threaded engagement with a 'sleeve83 secured'to the bottom of the plate 74. The screw 81 is rotatable by a hand wheel 84 at the end of "the table. The "mounting plate 74 is held down on 'the top of 'the table 1"3 by'ways 85 :engageable 'with the walls ofgrooves 74ain'the slides 74b (Fig.8

for the mounting plate.

asiases .When the piston rods 57 and 58 are retracted by the cylinder and piston means and 56, the end clamps 71 and 72 move away from the billet 12 because of the action of springs 75 and 76 and in addition the rollers 69 and 70 of the billet-engaging members 67 and 68 move away from the side of the billet 12 and pivot to the position shown in solid lines in Fig. 6. In this position the roller 70 engages the arm 86 of a switch 87 whose function will be described hereinafter. With the end clamps 71 and 72 and the billet-engaging members 67 and 68 in the position shown in Fig. 6, the billet 12 is completely free and may be rotated to expose another surface for grinding or may be removed from the table 13.

Billet turning The grinding apparatus is also provided with poweroperated, billet-turning equipment which is best shown in Figs. 2, 5 and 14. This equipment comprises a pair of fluid-actuated cylinder and piston means 83 and 89 mounted on the underside of the table 13 and having turning fingers 91 and 92 extending above the top of the table 13. When fluid such as air under pressure is introduced into the appropriate ends of the means 88 and 89, the fingers 91 and 92 move upwardly engaging the billet 12 on the underside thereof at a point to the front of its center of gravity. As the fingers move upwardly they tilt the billet 12 rearwardly until finally the billet falls on the side which was previously engaged by the rollers 69 and 70, thus producing a 90-degree rotation of the billet 12. When the air pressure is reduced, the fingers n 91 and 92 retract.

Movement of the billet 12 away from the front of the table is limited by the stop members 93 and 94 and, after it has been rotated 90 degrees as described, the billet 12 will rest in the position indicated in dotted lines in Figs. 5 and 8.

After the billet has been turned, fluid is again supplied to the cylinder and piston means 55 and 56 through the lines thereof which causes the rods 57 and 58 to move outwardly. Due to the arcuate configuration of the slots in the members 63 and 64, the end clamps 71 and 72 will not, during initial movement of the rods 57 and 58, move toward the ends of the billet 12 or will move only a small amount. As the rods 57 and 58 move outwardly, the members 67 and 613 pivot about their points of connection with the clamps 71 and 72 and the rollers 69 and 7d engage the side of the billet 12 which previously was under the grinding wheel and force the billet 12 forward on the table 13 and toward grinding position. As soon as the rotation of the members 67 and 68 proceeds to a point where the pins 65 and 66 pass the point 95 at the edge of the slot in the members 63 and 64, the end clamps 71 and 72 move closer to the ends of the billet 12 so that the fingers 96 and 97 on the clamps 71 and 72 move in front of the billet 12 and provide a forward stop therefor. At the end of the movement of the rods 57 and 53 the clamps 71 and 72 press tightly against the end of the billet 12 and the rollers 69 and 70 press tightly against the side of the billet 12 holding the billet 12 securely in grinding position.

The mounting plates 73 and 74 are also provided with a pair of rails 98 and 99 for receiving and supporting the billet 12 thereon and with arms 100 and 101 each having a pair of shoes 102-105 for operating the arms of switches 106-4.09 mounted on a fixed frame supported from the foundation 40. The switches 106-109 are employed for controlling movement of the table 13 in the manner hereinafter described and the switches 106 and 108 are operated respectively by the shoes 102 and 103 and the switches 107 and 109 are operated respectively by the shoes 105 and 104.

Billet storage and loading Referring to Figs. 5 and 9-13, the billet loader apparatus employed to deposit a billet on the table 13 and,

if aground billet is on the table 13, for removing the ground billet from the table 13 comprises an inclined billet storage racklll supported by a frame having vertical legs 112 and having horizontal cross braces 113. A pair of longitudinally extending I-beams 114 and 115. are mounted on the cross braces 113 and are held in spaced relationship by a pair of cross pieces 116. The cross pieces 116 support a fluid-actuated cylinder and piston means 117 having a piston rod 118 extending therefrom and connected to a bracket 119 on the underside of a pusher ram 120. The pusher ram 120 is U- shaped, as is best shown in Fig. 11, and is arranged to slide back and forth on I-beams 114 and 115, the ram 120 being guided on the tops of I-beams 1114 and by guides 121-424. Each side member of the ram includes a longitudinally extending plate 125 and 126 to which is secured, such as by welding, pairs of channels 127 and 128 and 129 and 130, the channels 127-4130 being spaced apart so as to receive therebetween billetdischarging links 131 and 132 and billet-feeding links 133 and 134. These links are pivotally supported on cross pins 135-438 which are secured to the channel members 127-130. The channels 127130 are braced by a pair of angle members 120a and 1211b fastened thereto and to the rear member 1200 of the ram 120.

The links 131-134 are constructed so as to stand normally in the upright positions shown in Figs. 813 and immediately in front of the links 131-134 below their pivot pins are angle brackets 139--142 which are secured to the channels 127-130 so as to prevent the links 131- 134 from tilting in a counter-clockwise direction as viewed in Fig. 9 but still permitting them to tilt in a clockwise direction as viewed in this figure.

The cylinder and piston means preferably is operated by air and has a pair of fluid lines 143 and 144 connected thereto for the purpose of admitting such air thereto and thereby moving the piston rod 118 and with it ram 120 either toward or away from the table 13. The supply of air to the lines 143 and 144 is controlled by the threeway valve 145 having an air line 146 connected thereto and controlled by the solenoids 147 and 148. Switch 149 operated by the pusher ram 120 and switch 150 operated by the bracket 119 are mounted on the members 112 and 115 respectively for controlling the operation of the apparatus in the manner hereinafter described.

The storage rack 111 is adapted to support a plurality of the billets 12 at such an angle that gravity tends to force them one by one onto a billet land or waiting area 151, the surface of the billet land 151 being inclined rearwardly of the loading apparatus so as to hold the bottom-most billet in the position shown in Fig. 9, thereby retaining the remainder of the billets on the surface of the rack 111.

As is best shown in Figs. 1l14, the rails 93 and 99 have intermediate surfaces 152 and sloping end surfaces 153 and 154. The intermediate surfaces 152 are raised above the top of the table 13 a distance greater than the upper surface ofthe pusher ram 120 when it is moved forward for the purpose of loading a billet 12 on the rails and the rails 98 and 99 are spaced apart a distance suflicient to permit the forward end of pusher ram 120 to pass therebetween.

When it is desired to place a new billet on the table 13 for grinding, the loading apparatus is in the rest position shown in Fig. 9. The grinding wheel 11 is raised from the grinding position shown in Fig. 9 and the billet whose grinding has been completed is unclamped so that the clamping members 67 and 68 are in the position indicated in solid lines in Fig. 6. An unground billet 12 which has fallen by gravity on to the billet land 151 is ready to be engaged by the links 133 and 134. The valve 145 is operated by one of the solenoids 147 and 148 so that air under pressure is admitted into the cylinder and piston means 117 through the line 143 causing the piston rod 118, and hence the pusher ram 120, to

move forward toward the 'table '13. .It will 21se- *iiiiderstood, o't" course, that prior to operation df he "cylinder and piston means 1*17tl1'e table "113 win-have beeninoved to its right-hand position as viewed in Fig. 5 so ;as to permit the pusher ram .120 to enter the space bet-ween the rails 98 and 99.

As the ram moves forward the feeder lin'ks -13?) and 134 engage the unground billet on the land 151 and push it .onto the rails '98 and "99 in 'Il'lB manner indicated in Figs. '12 and 13. As soon as the billet on the land 1 is removed, the next billet on the rack 1'1'1 drops down on the land 151 and hence is in position for the next loading of the table 13. When the billet which is being loaded on the rails 98 and 99 reaches th'einclined surfaces 154 on the rails, it will be guided up the inclined surfaces 154 to the middle surfaces 152 As the billet being loaded reaches the?beginning of' thc surfiaces 152, as shown in Fig. 1-2, the discharge links 131 and 132'engage the ground billet which is on thesur'faces 152 and push it forward to the inclined surface 153 asshown' in reversal being accomplished by another operati'omof the valve and admission of air into the cylinder and piston means 117 through the line 144, and moving the-ram 120 to its fully withdrawn position shown in Fig.9 the cylinder and piston means '55 and 5.6 may be operated causing the unground billet to move from the'irear portion of the surfaces 152 to the forward portionofthe surfaces 152 where it is ready for grinding'in the manner set forthabove.

As the ram 120 is withdrawn, the discharge links 131 and 132 strike the unground billet on the rear-portion of the surfaces 152, but due to the fact that they are permitted to rotate in the clockwise direction as viewed in Figs. 9, l2 and 13 the links 131-and 132 do notdisturb the ungronnd billet but instead merely slide under the billet. the teed links l33'and B iengage the unground billetion the land 1151 butdue to their ability to rotate as mentioned above they merely pass under the unground billet on the land151.

Upon reference to Figs. 11 and 14, it will be seen that the stop members l3 and '94- also are in the form of rotatable links. Thus, the stop members '93 and "94 are mounted on U-shaped brackets 155 and 156 which are secured to the top of the table The stop members 03 andi i are rotatablymounted on-the brackets 155 and 156 by a pair of pins 157 and 'lSdand-zire rotatable in the clockwise direction as viewed in Fig. 14, rotation in the counter-clockwise direction being prevented by engagernent of the lower end of the members 93 and 94 with upwardly extending portions 159 and 160 of the brackets '155 and 156. Thus, the stop m'embers 93 and 94 rotate during loading of the unground Ibillet :and movement of-the unground billet to the grinding-position and thereby slide under the unground'billet as it is moved.

However, when the billet is turned soasto presentaznew face to the grinding wheel, .the :mernbersQS and 194 are in the vertical position indicated in Fig. 14 and ;prevent the billet as it is turned from moving backward beyond the-desired position upon the rails 98 and '99.

Fluid actuating systems As mentioned above, the various *fluid-actuated cylinder and piston means may be actuated by air or by a liquid, such as "oil, "under pressure. 'In the preferred form bf the invention, the cylinder and =piston means employed Similarly, 'as the ram 120 -'is 'further withdrawn, I

for the reciprocation of the "table 13, the beam 23 and the weight '30 are actuated "by oil under pressure and the cylinder and piston means employed for lifting the grindirrg wheel T1, turning of the billet 1'2, clamping of the billet 12 and reciprocation of the loader 120 are actuated by air, air being preferred for the operationof the latter cylinder and piston means because of the speed and cushioning effect obtainable.

Figure 15 shows schematically theoil-operated cylinder and piston means and their connections with the valves controlling the operation thereof and show the electrical controls which are operated either directly or indirectly by the cylinder and piston means. Referringto Fig. 15, oil is supplied under pressure to the line 161 and is conveyed to the various cylinder and piston means through the control valves .by .lines 162164, the various lines being equipped with conventional shut-oh and pressurerelief valves which have not been shownin the drawings for purposes of simplicity. Oil which is by-passed from the :system'or which is returned to the source by the various-cylinders when the direction of movement is rchanged is returned to the source through the line 165.

The supply of oil to the weight-operating cylinder and piston .means 32 is controlled by a two-way valve 166 which is controllable electrically by the solenoids 167 and 16S. Counterweight 30 in its rearmost position, i. e., the ,position in which the .grindingwheel 11 is lifted by the weight 30 from the bidet 12, strikes the arm of a limit switch 169 whose function will hereinafter be explained.

The supply of oil to the cylinder and piston means 53 which reciprocates the table 13 is controlled by a twoway valve 170 and .a bypass valve 171. Valve 170 is electrically controllable by solenoids 172 and 173 and 'by-pass valve 171 is electrically controllable by solenoid 174. Va1ve170 permits fluid to flow into one end or the other of the cylinder and piston means 53 and hence causes reciprocation of the table 13, and by-pass valve 171 when de-energized cuts oit the flowof fluid to both the valve 170 and to the cylinder and piston means 53 stopping the table 13. As previously explained, shoes 102-105 mounted on arms 100 and 101, which in turn are movable withthe table 13, operate the arms of reciprocation control switches 108 and 109 and, when the grinding wheel 11 overruns the billet '12, operate the limit switches 106 and 107, the function of these switches being explained in further detail hereinafter.

The supply of oilto the cylinder ahdpiston means 36 for reciprocating the beam 23 on which the grinding wheel 11 is mounted is controlled by the valve 175 and the by-pass valve 176, these valves being electrically .controllable by solenoids 177179 connected as shown by Fig. '15. Valve 175 permits oil to enter one end or the other of .the cylinder of cylinder and piston means 36 causing beam 23 to reciprocate, whereas when by-pass valve 176 is deeenergized the supply of oil to the valve 175 and the cylinder'and piston means 36 iscut oif causing the beam 23 on which the grinding wheel 11 is mounted to stop.

A shoe or cam 180 is mounted on the beam 23 as shown in Fig. 3 and, therefore, is movable with the-piston rod 37 of the cylinder and piston means 36. Thiscam or shoe ltitl engages the arms of a pair of reciprocation control switches 181 and 182, also shown in Fig. l, and these switches control the reciprocation of the beam 23 in the manner described hereinafter.

.As shown in Fig. 4, a further cam or shoe 183 is mounted on the opposite side of the beam 23 and, therefore, is'also movable with the piston rod 37 of the cylinder and piston means "36. This cam or shoe 183 engages the arms of a pair of switches 184 and 185'Which reduce the pressure applied to the grinding wheel 11 at the corners of a billet being ground in the manner described infurther detail hereinafter.

.Figure 16 illustrates schematically'the 'controls forithe asiases air-actuated cylinder and pistonmeans. In Fig. 16 it will be seen that air under pressure is supplied to the system through a line 186 connected to branch line 146 supplying air to the loader cylinder and piston means 117, branch line 187 supplying air to the clamping cylinder and piston means 55 and 56, branch line 188 supplying air to the beam-lift cylinder and piston means 39 and branch line 189 supplying air to the billet-turning cylinder and piston means 88 and 89. These lines are equipped with conventional pressure regulators and shut off the valves which have not been shown for the sake of simplicity.

The supply of air to the double-acting cylinder and piston means 117 is controlled by the two-way valve 145 which in turn is electrically controllable by the solenoids 147 and 148. In its normal or rest position the loader 120 engages the arm of switch 149, and in its forward position the bracket 119 of the loader 120 engages the arm of switch 150, the functions of these switches being described hereinafter.

The supply of air to the double-acting cylinder and piston means 56 is controlled by the valve 190 which in turn is electrically controllable by the solenoid 191. When the solenoid 191 is energized, the valve 190 admits air to the cylinder and piston means 55 and 56 at the end thereof which causes the clamping members 67 and 63 to pull away from the billet on the table 13. On the other hand, when the solenoid 191 is de-energized, valve 190 supplies air to the opposite ends of the cylinder and piston means 55 and 56 causing the clamping members 57 and 53 to engage and clamp a billet on the table 13. When a billet is in its grinding position on the table 13, it engages and operates the arm of a switch 198 and, when the billet is in its turned position or has just been loaded on the table 13, it engages and operates the arm of a switch 199, the function of these switches being described hereinafter.

The supply of air to the cylinder and piston means 39 is controlled by a valve 192 which in turn is electrically controllable by a solenoid 193. When the solenoid 193 is energized, the valve 192 admits air to the end of cylinder and piston means 39 which causes the piston rod 42 to pull the end of the beam 23 to which it is attached in the downward direction, whereas when the solenoid 193 is rile-energized the supply of air to the cylinder and piston means 39 is cut oil and the air in the cylinder and piston means is exhausted through vent 19 1. When the rod 12 has moved in the downward direction sufiiciently to lift the grinding wheel 11 from the face of the billet, the arm 42a engages and operates the arm of switch 421: whose function is described hereinafter.

The supply of air to the billet-turning cylinder and piston means 88 and 89 is controlled by a valve 195 which is electrically controllable by a solenoid 196. When the solenoid 196 is energized, the valve 195 permits air to flow into the end of cylinder and piston means 88 and 89 which causes the fingers 91 and 92 to raise. When the solenoid 196 is de-energized, the supply of air to the cylinder and piston means 88 and 89 is cut off and the air in these means 88 and 89 is exhausted through a vent 197.

Wheel pressure control Fig. 17 is an electrical circuit diagram of the electrical system employed for controlling the grinding apparatus of my invention, and as shown in Fig. 17 the motor 27 which may, for example, be a three-phase motor is connected to a suitable source of electrical power through conventional motor-starting apparatus 200. As described in the aforesaid copending applications, the force applied to the grinding wheel 11 to hold it against the face of a billet is automatically adjusted in accordance with the load on the grinding wheel 11. To accomplish this result a pressure control circuit illustrated diagrammatically by the rectangle 201 is coupled to the input circuit of the motor 27 by a transformer 202 which may, for example,

19 be a current transformer. The pressure control circuit 201 is described in detail in my aforesaid copending application Serial No. 279,789 and, briefly, the circuit when set for automatic operation decreases the downward pressure on the grinding wheel when the current drawn by the motor 27 increases and vice versa; By setting or" the automatic control to the correct position the pressure will adjust itself so that the input current to the motor 27 has a predetermined value. Such automatic control is desirable not only because it produces an even grinding of the surface of a billet but also because the undesired material on the surface of the billet is removed at a constant rate.

When the control handle 203 of the pressure control circuit 201 is set in the position marked Manual, the contactor 204 is moved in the downward direction interconnecting the contacts 205 and 206 and the contactor 207 is permitted to move upwardly and to interconnect the contacts 208 and 209. In this position of the control handle 203 a circuit for energization of the solenoid 167 of the weight control valve 166 is established from ter minal B to terminal A of the power source 2111 through contacts 208 and 209, the contacts of limit switch 169, contacts 205 and 206 and solenoid 167. Energization of the solenoid 167 causes the weight 30 to move rearwardly of the beam 23 lifting the wheel 11 from a billet on the table 13. When the weight 30 reaches the end of its rearward movement, it operates limit switch 169 breaking the energizing circuit for the solenoid 167 and sto ping the further supply of fluid to the cylinder and piston means 32. In this position of the control handle 2113 the grinding wheel may be pressed against a billet and recip' rocated manually by an operator who may grasp and manipulate the handle 211 (Fig. 3) adjacent the grinding wheel 11.

When automatic control of the downward force on the grinding wheel 11 is desired, the control handle 203 is moved from the position shown and toward the position marked Automatic. Such movement releases conta tor 204 disconnecting contacts 205 and 206 and moves contactor 207 in the downward direction interconnecting contacts 212 and 213. Interconnection of the contacts 212 and 213 connects the contacts 214 and. 215 of the relay 216 to terminal B of the power source 210. Contacts 217 and 218 of relay 216 are connected respectively to the ends of solenoids 168 and 167 which control the operation of valve 166. The armature 219 of the relay 216 having a contactor 220 thereon is urged by spring 221 toward a position such that it interconnects contacts 214 and 217. Energization of the coil of relay 216 moves the armature 219 in such a direction that it interconnects contacts 215 and 218 and in an intermediate position the contacts are not interconnected. The control circuit 2611 supplies a current to the coil of relay 216 which is proportional to the current drawn by the motor 27 and the control handle 203 adjusts the magnitude of this current.

Assuming that the control handle 203 is moved from the manual toward the automatic position, there will at first be substantially no current in the coil of the relay 216 because, due to the fact that the weight 30 is at the rearmost position, the current drawn by the motor 27 is relatively small. Thus, the contactor 220 will interconnect contacts 214 and 217 energizing solenoid 163 through a circuit extending from terminals B to A of source 210 through contacts 212, 213, 214 and 217 and solenoid 16?. This will cause the cylinder and piston means 32 to move the weight 30 in a forward direction and in turn cause the grinding wheel 11 to lower to the face of a billet on the table 13. As the weight 30 continues to move forward the pressure exerted by the grinding wheel 11 on the face of the billet will increase causing the current drawn by the motor 27 to increase. An increase in the current drawn by the motor 27 will cause an increase in the current in the coil of relay 216 and will, after a predetermined current isreached, move the armature 219 to the right as shown in Fig. 17 and will,.therefore, disconnect n contacts 214 and 217 brealing the energization circuit for the solenoid 168.

As long -as the current in the coil of relay 216 does not exceed a predetermined value, the contactor 220 will remain in an intermediate position between the-contacts 214- and 217 and contacts'215 and 218. If, however, for some reason, such :as a change in the surface characteristics of the billet or the grinding wheel, the current in the coil of relay 216 increases a suflicient amount the contaetor 220 will interconnect contacts 215 and 21h establishing a circuit from terminal A =to-terminal B through contacts 21.2, 213, 215, 218 and solenoid 167. Accordingly, the cylinder and piston means 32 will move "the weight 3t) rearwardly reducing the downward force on the wheel 11 and hence the current drawn by the motor 27. This in turn will reduce the current in the coil of relay v2 146 and will permit the armature '21 9'to move to the left as viewed in Fig. 17 and will break -the-energization circuit for the "solenoid 167. In this "manner thedownward force on the grinding wheel 1 1 is automatically controlled in accordance with the amount of energy supplied to the motor 27. Further details of the automaticcontrol circuit 201 are set forth in the aforesaid copending application Serial No. 27 9, 789.

If when the grinding wheel 11 is at the corners of a billet the value of the downward force is maintained the same as its value when the grinding wheel is in engagement with a portion -ofthe face spaced from the corners of the billet, the grinding wheel will have a tendency to round such corners. Accordingly, switches 184 and .1255 are provided for the purpose of reducing the-downward force by a predetermined amount .as .thegrin'ding wheel approaches suchcorners. These switchescontrol the circuit 201 in the manner described in the aforesaid .copending applicationSerial No. 279,789 and their function need not be described in further detail herein.

Safety lift and timing control A safety lift circuit 222 of the type "described in the aforesaid copending application Serial No. 279,789 is also provided for the purpose of energizing the lift solenoid 193 and hence lifting the grinding wheel 11 rapidly and independently of the control circuit 291. .In the position of control :handle 223 .rnarked Lift the grinding Wheel 11 is lifted and the handle v223i must be :moved to the position marked Reset after the wheel 11 has been lifted by movementof the handle 223 to the Lift position by an operator or by actuation .of one of the overtravel switches 106 and 107. The over-travel switches 1136 and 107 (Figs. 2 and are positioned so that, if the table 13 moves the .billet 12 out from under thegrinding wheel 11, switch 107 is actuated by shoe 1195 or switch 106 is actuated by shoe 102 causing the wheel 11 to lift and preventing damage to the table or the equipment mounted thereon.

A timer 224 of the type disclosed in the aforesaid application Serial No. 279,789 is provided for the purpose of reciprocating .the table 13 .along a short ,path when it is desired to provide additional grinding for a portion of the surface of the billet being ground. Timer 224 whenconnected intoathecircuitalternately energizes solenoids 172 and 173 and produces a short reciprocatory movement of the table 13.

Single face grinding controls For purposes of explanation, assume that the mounting plates 73 and 74 have beenadjusted so as to receive a billet 12 thereon in the manner shown in Figs. 2 and 5, a billet 12 is clamped in grinding position .as shown in these figures, ltable .13iis being reciprocated, grinding wheel 11 hascommenced its reciprocation .beginningat the edge of the billet 12.nearestthegrinding wheelmounting frame ZSandhencethexfonwardzedge of .table 13, the automatic control circuit .201 .has been set to fgivethe desired grinding pressure, vthe motor.27 being in operation, the control gized, on-oif switch 225 has been manually actuatedantl the timer 224 is out of operation. As the :table 13-weciprocates the shoes 103 and 104 strike respectively the arms of switches 108 and 109 (Figs. 5 and 17) causing the direction of movement of the table 13 to be'reversed as the grinding wheel 11 reaches each end of the billet 12. As shown in Fig. 17 switch 108 when 'moved in the downward direction completes a circuit from terminal B to terminal A of the power source 210 through the contacts of on-ofr' switch 225, contacts 226 and 227 'ofsw'itch 108 and solenoid 172. When switch 109 is actuated-and hence switch 1118 is released, switch 109 completes a circuit from terminals B to A through switch 225', contacts from the forward edge of the table 13, the shoe cream 13'?) actuates the switch 182 (Figs. 3 and 17) and completes an obvious circuit for energization of the solenoid 178. Energization of the solenoid 178 reverses the direction of fluid flow to thecylinder and piston means '36 causing the direction of movement of the wheel 11 to reverse. The valve 175 remains in the position to which it is operated by the solenoid 178 until the solenoid 177 is operated. Solenoid 177 may be-energi-zed in the manner hereinafter described and both solenoids 177 and 17-8 may also be energized by manual operation of the switches 231 and 230 respectively.

As pointed out above, when solenoids 174 and 179 are energized, fluid under pressure is supplied .to t-he valves 17%) and 175 which control the reciprocation of the table 13 and the grinding wheel 11. However, when the solenoids 174 and 179 are .de-energized, as they :may be by manual operation of the switches 232 and 233 and by release of by-pass relay .238 :as wellas actuation ofiswitch M8, the supply of fluid to the valves :and is :cut 011 so that both the table and :the wheel stop. Normally, the switches 232 and 233 .are nnoperated so that both solenoids 174 and 179 are energized by oircuitscompleted through the contacts 234-437 of 'normallyenen gized relay 238. Thus, :the energizing circuit. for sole mold 179 may be traced from lead 239 which is connected to terminal B of source 210 to lead .240 which is :con nected to terminal A of source 210 through contacts 234 and 236, contacts of switch .232 and solenoid .179. The energizing circuit for solenoid 174 may be traced from lead 239 to lead 240 through contacts 235 and 23.7, lead 241, contacts of switch 233 and solenoid 1.74. Solenoid 174 is also separately energized, .when .switch 108 is unactuated, by a circuit which may be traced from lead 242 connected to terminal B to lead 240 through contacts 243 and 244 of switch 108, lead 245, contacts of switch 233 and solenoid 174. Thus, both operation of switch 108 and release of relay 238 is required to deenergize solenoid 174 as long as the manual switches/232 and 233 are 'unoperated.

Switch 181 is provided with a pair of normally connected contacts 246 and 247, contact .247 being connected to lead 24d and contact 246 being connected to one end of the coil of relay 238*. These contacts .246 :and 247 complete a circuit for the coil of relay 238 extending from lead 239 to .2411 and, :therefore, relay.238 is maintained .in an energized condition until the switch .181 is operated. .As viewed in Fig. 3, switch 151 isioperated when the .beam 23 on which the grinding wheel .11 :is mounted is in aposition .to theleft of the position shown and the position of the switch 181 with respect -to the shoe or cam 189 is adjusted so that the switch 181 is operated when the billet-engaging portion of the face of the wheel 11 is at the forward edge of the billet 12. Thus, when the grinding wheel 11 reaches this position, the switch 181 is operated disconnecting contacts 246 and 247 and tie-energizing relay 238. De-energization of relay 233 disconnects contacts 234 and 236 and de-energizes solenoid 179 stopping the movement of the beam 23 which carries the grinding wheel 11. At the same time, relay 238 disconnects contacts 235 and 237.

Operation of switch 181 also interconnects contacts 248 and 249 completing a circuit for energization of lift relay 259. The energization circuit for relay 250 may be traced from lead 251 connected to one end of transformer 352 to lead 264 connected to the opposite end of transformer 352, through lead 253, contacts 254 and 255 of normally de-energized recycle relay 256, lead 257, lead 258, contacts 248 and 249, lead 359, contacts 266 and 261 of normally tie-energized restart relay 262, lead 263, and the coil of relay 259. When relay 250 is operated it interconnects its contacts 265 and 266 establishing a locking circuit for its coil and it interconnects its contacts 267 and 268 completing an energizing circuit for the lift solenoid 193 extending from lead 239 to lead 240 through contacts 267 and 268, lead 269 and solenoid 193.

Shortly after switch 181 is actuated, switch 108 is actuated by shoe 1193 and, although the delays may be such that switch 108 is operated after lift solenoid 193 has been energized, the delay before solenoid 193 is energized also may be arranged in a well-known manner so that switch 198 is actuated before movement of the lift piston rod 42. Switch 168 preferably is of the breakbefore-make type so that contacts 243 and 244 are disconnected before contacts 226 and 227 are connected. Thus, although switch 108 completes the energizing circuit for the solenoid 172 which would normally cause the table 13 to move to the left as viewed in Figs. 1, 2 and 5, the solenoid 174 has previously been de-energized because contacts 243 and 244 have been disconnected. As pointed out above, when solenoid 174 is de-energized the table 13 is brought to rest and, because the table 13 is brought to rest immediately after actuation of the switch 198, the table stops in its extreme right-hand position as viewed in Figs. 1, 2 and 5.

Energization of the lift solenoid 193 by the previously described circuit causes operation of the cylinder and piston means 39 and, when the wheel 11 is lifted from the face of the billet by a predetermined amount, the arm 42a actuates the switch 42b. Actuation of switch 42b completes an energizing circuit for the billet unclamping solenoid 191 which may be traced from lead 242 to lead 249 through lead 279, contacts 271 and 272, lead 273, contacts 276 and 275 of relay 256, lead 276 and solenoid 191. Energization of the solenoid 191 causes the clamping members 67 and 68 as well as the end clamps 71 and 72 to move away from the billet 12, thereby releasing the billet.

If desired, the cycle of operations may be interrupted at this point by omission of contacts 277 and 278 of clamp operated switch 87 so that before further operations take place it is necessary for an operator to energize billet-turning solenoid 196 by actuation of manual switch 279 or to discharge the ground billet and load a new billet by actuation of manual loading switch 280. However, in the preferred form of the invention, the operations are continued automatically so that the billet which has been ground on one face is automatically turned, reclamped and ground on the next face.

Multiple face grinding controls When clamping member 68 reaches the full release position as shown in Fig. 6, it strikes the arm 86 of switch 87 interconnecting contacts 277 and 278 which complete an energizing circuit for billet-turning solenoid 196, which circuit may be traced from lead 242 to lead 240 through contacts 281 and 282 or normally de-energized reload relay 233, lead 234, contacts 277 and 278, lead 235, contacts 286 and 237 of switch 199, lead 288 and solenoid 196. Energization of solenoid 196 causes operation of cylinder and piston means 88 and 39 and rotation of the billet 12 which is square in cross section through 90 degrees as well as movement of the billet 12 from the position shown in solid lines in Fig. 5 to the position indicated in dotted lines in Fig. 5.

When the billet 12 is in the position shown in dotted lines in Fig. 5, it actuates the billet-turned switch 199 disconnecting contacts 286 and 287 and de-energizing solenoid 196 causing the turning fingers 91 and 92 to return to their normal positions. Actuation of switch 199 also interconnects contacts 289 and 299 completing a circuit for energization of recycle relay 256 which may be traced from lead 242 to lead 249 through contacts 281 and 282 of reload relay 2S3, lead 284, contacts 277 and 278, lead 235, contacts 289 and 290, lead 291, lead 292 and the coil of relay 256, the opposite end of the coil of relay 256 being connected to lead 240 by lead 293.

As will be explained in further detail hereinafter, the arm 294 of stepping relay 295 having the stepping coil 296 and resetting coil 297 is in engagement with the contact numbered 1 during the grinding of the first face of the billet 12. When relay 256 is operated it completes an energizing circuit for the stepping coil 296 which may be traced from one terminal of transformer 298 to the other terminal of transformer 298 through coil 296, lead 299, contacts 309 and 301 of relay 256 and lead 392. The arm 294 of relay 295 does not move upon energization of coil 296 but instead. moves to the next contact when the coil 296 is subsequently tie-energized.

At its contacts 363 and 304 relay 256 completes a locking circuit for its coil extending from lead 242 to 240 through lead 270, contacts 365 and 396 of lift-operated switch 422;, lead 397, contacts 303 and 394, lead 292, the coil of relay 256 and lead 293. At its contacts 308 and 309 relay 256 prepares part of a circuit for subsequent release of relay 256 and at its contacts 310 and 3111 relay 256 completes part of a circuit for subsequent operation of restart relay 262.

When relay 256 is operated it disconnects contacts 274 and 275 and hence breaks the energization circuit for billet unclamping solenoid 191 causing the clamping members 67 and 68 and end clamps 71 and 72 to engage the billet 12 and move it from the position shown in dotted lines in Fig. 5 to the position shown in solid lines in Fig. 5 in the manner previously described, the position of the billet shown in solid lines in Fig. 5 being the grinding position of the billet. As the billet is moved from its turned position to the grinding position the switches 87 and 199 are released and in the grinding position the switch 198 is actuated by the billet or, if desired, by the clamping mechanism.

The switches 87 and 199 are arranged so that the contacts 277 and 278 of switch 87 are disconnected before the contacts 286 and 287 of switch 199 are connected. Release of switch S7 at first has no effect because, although it breaks the initial energizing circuit for relay 256, relay 256 is held by the locking circuit previously described. However, when contacts 286 and 287 are again connected by the switch 199 the circuit previously established by contacts 277 and 278 for energizing billet-turning solenoid 196 is open thus preventing turning of the billet when it is returned to the grinding position.

Operation of switch 198 which indicates that the billet is ready for grinding completes an energizing circuit for restart relay 262 which may be traced from one terminal to the other terminal of transformer 312 through lead 313, contacts 310 and 311 of relay 256, lead 314, contacts 315 and 316 of switch 198, leads 317 and 318 and the coil of relay 262. Switch 198 also completes a circuit for short;-

as'l a ses circuiting the coil of lift relay 25tl'and .hence for releasing.thisnrelay,'the circuitbeing traced fronrone end to the other of the coil of relay 258 through leads 319,-contacts 328 and 321 of switch 198, lead 322, contacts 308 and 309 .of relay 256 and lead 323 which is connected to one end of the coil of relay 250. Gperation of relay 256 breaks the previously established energizing circuit for lift relay250 at its contacts 254 and 255 andcoperation ofrelay 262 adds a further discontinuity in the energizing circuit forrelay 25G) 'forpurposes hercinaf er explained. Release of relay .258 breaks its locking circuitat contacts 265 and 266and breaks the energizing circuit for lift solenoid 193 at its contacts 267 and 268. De-energization -of lift solenoid 193 permits the grinding wheel to lower to the surface of the billet in the grinding position and lowering of the grinding wheel 11 releases switch 42b. Release ofswitch 42b disconnectscontacts 271 and 272and ther by prevents re-energization of the billet unclarnping solenoid 191 when the relay 256is subsequently released. 'The release of switch 42b also disconnects contacts 305 and 306 breaking the locltingcircuitfor relay .256 and releasing relay 256.

Although release of relay 256 interconnects contacts 254 and 255 which form part of the .energization circuit for lift relay 25d, thecircuit is interrupted at the contacts 260 and 261. of restart relay 262. Release of relay 256 also interconnects contacts 324 and 325 which completes a hold circuit for the relay 2'62, either the delay in release of relay 262 being sufficient to hold the relay 262 until the contacts 324 and 325 are interconnected or the contacts 324 and 325 being interconnected before the contacts 310 and3'11 are disconnected. The circuitjust established for holding relay 262 may be traced from one terminal to the other terminal of transformer 312*through lead 3-13, contacts 324 and 325, lead 326, contacts 327 and 328,1ead 329,0ontacts 338 and 331, leads 317 and 318 and the coil of relay 262. Release of relay 256 also causes coil 296 to become de-energized and hence causes arm 294 to step forward to contact numbered 2.

Operation of restart relay 262 also completes an energizingcircuit for by-pass relay 238 and forward solenoid 177, by-pass relay 238 energizing the forward-back bypass solenoid 179 and the left-right by-pass solenoid 174 permitting fluid to be supplied to the valves 178 175 and causing the table 13 and the wheel 11 to reciprocate in the manner previously described. Energization of the [forward solenoid 177 determines the initial direction of movement of the grinding wheel. '11. The circuit'for'energization of by-pass relay 238 may be traced from lead 240 .to lead 239 through lead 293, contacts 332 and 333 of relay 262, lead 334, lead 335 and the coil of relay 238. The energization circuit for solenoid 177 may be traced from lead 239 to lead 248 through lead 336, contacts 337 and 338 of relay 262, lead 339 and solenoid 177.

It will be noted that until the grinding wheel 11 moves forward by a predetermined amount the switch 181 is actuated and, therefore, no energizing circuit for the relay 238 is established through the switch 18.1. Accordingly, one of thefunctions of the restart relay 262 is to energize by-pass relay 238 and hold it in energized condition until the .switch 181 is released and as soon as switch 18-1 is released the restart relay 262 is also released. Thus, either .by suitable provision of a slow release time for'the relay 262 or by interconnection of contacts 2% and 247 of switch 18-1 before disconnection of contacts 32.7 and 328 of switch 181, the contacts 246 and 247 are interconnected before the energizing .circuit for by-pass relay 238 extending through the contacts 332 and of relay 262 is broken. When contacts 327 and 328 are disconnected by release of switch 181 the previously described holding circuit for the restart relay 262 is broken. Also, by release of switch 18-11 a second discontinuity in the energizing circuit for relay 250 is provided at the contacts 248 and 249 so that, even though both relays 256 and 26221136 released, theslift relay 250 does not again become energized.

After switch 181 and restart relay 262 are released as aforesaid, thejgrinding operation continues in the manner previously described 'so that the newly presented face of thebillet $12 is traversed by the grinding wheel 11,-"the grinding wheel 11 moving forward to the rear edge-of the billet 12 and-returning to'the forward edge of the billet 12. When the grinding wheel 11 again reaches the for ward edge of the billet 12 the switching operations just described repeat, the only difference being that stepping relayl295 steps from contact 2 to contact 3. In this manner all four facesof the billet are ground, it being understood that if the billet has a number of faces other than four thelste'pping relay 295 would be provided with acorresponding number of contacts.

During grinding :of the fourth and last face of the billet 12 the arm 294 is on contact No. 4. However,.

during this ,portion of thegrinding, the arm .294 does not complete a circuit because when arm 294 reaches contact No. -4 the switch 87 is released. However, when the switch '87 is actuated by :the clamping mechanism after the fourth face has been ground, switch 87 completes a circuit for energization of reload relay 283. Thiscircuit may be traced from one terminal to the other terminal of transformer 298 through'lead 340, the coil ofreload relay 283, lead 341, contacts 342 and 343 of switch :87, lead .i344,-conta-ct N0. 4, arm 294 of relay 2'95 and .lead 345. Switch 187 is ofthe type in whichcontacts 342 and 343 :are:connected before contacts 277 and 2178 are;connected -so that relay 283 disconnects its contacts 281 and 282 before contacts 277 and 278 are connected.

Thus, relay 283 interrupts the previously described ener-' gizing circuit for turning solenoid 196 so that after the fourth face is ground 'and the billet is unclamped the turning apparatus does not operate to turn the billet. The automatic cycle of operations may be discontinued at this point so that it is necessary for an operator to intervene before grinding will be resumed. Thus, .if'the circuits hereinafter described are omitted, resumption of the grinding cycle can beinitiated by operation of manual loading switch 280 to' load a billet on the table 13 and then by operation of manual resetting switch 346, the switch 346 returning the arm 294 of stepping relay L295 to contact numbered 0 and releasing relay 283 to initiate the clamping, grinding and turning operations previously described. It will be noted that when a billet is loaded on the. table '13 it will atfirst be in the position shown in dotted lines in Fig. 5 and, therefore, the switch 199 .is

.actuated preventing energization of turn solenoid 196 when the relay 283 is manually released by operation of switch 346.

Automatic reloading and recycling controls In the preferred embodiment of the invention a billet from the loader is automatically transferred to the table of the grinding apparatus and the ground billet is discharged. Also, the cycle of operations is automatically re'initiated. Of course, provision is also made to prevent 'reinitiat'ion of the grinding operations whenthe'reis no billet on the loadingrack and the last billet on "the table has been ,ground.

In the preferred embodiment of the invention operation of the reload relay 283 completes a holding circuit for .the lift relay 250 so that the grinding wheel 11 not be lowered as long as the reload relay 283 is energized. This circuit may be traced from lead 251 to lead 264 through lead 347 which is connected to lead 251, contacts 348 and349 of reload relay 283, leads 350 and 258, contacts 248 and 249 of switch 181, lead 359, contacts 260 and 261 of restart relay 262, lead .263 and the relay 283 isoperated it completes .a circuit for energiza-.

17 tion of' the solenoid 147 which causes the ram 120 to move forward; This circuit maybe traced between terminals B and A of power source 210 through switch 225, lead 242, contacts 351 and 352 of reload relay 283, lead 353, contacts 351 and 355 of switch 149, lead 356, solenoid 147 and leads 357 and 358. After solenoid 147 is energized, ram 120 moves forward carrying a billet from the land 151 on the loader rack to the rails 98 and 99 and discharging the ground billet to the conveyor 15 in the manner previously described. Although the switch 149 opens when the ram 120 moves forward, de-energization of the solenoid 147 does not stop the ram or cause it to reverse its direction, the valve 145 remaining in the position to which it was actuated by solenoid 147. However, release of the switch 149 prevents at its contacts 359 and 360 resetting of the stepping relay 295 when the new billet is loaded on the table 13 and delays resetting of the relay 295 until the loader has returned to its rest position.

When the ram 120 reaches its forward position and hence places the new billet in the position shown in dotted lines in Fig. 5, the switch 150 is actuated. The loader return solenoid 148 is energized by a circuit extending from lead 242 to lead 358 through lead 361, contacts 362 and 363 of switch 149, lead 364, contacts 365 and 366 of switch 150, lead 367 and solenoid 148. Energization of solenoid 148 causes the ram 120 to return to its rest position and hence causes reactuation of switch 149.

When switch 149 is again actuated it completes the circuit for energizing resetting coil 297 of relay 295. This circuit may be traced from one terminal to the other terminal of transformer 298 through lead 368, contacts 369 and 370 of switch 199 which has been actuated by the billet which was deposited on the table by the loading apparatus, lead 371, contacts 359 and 3.60 of switch 149, lead 372, contacts 373 and 374 of reload relay 283, lead 375 and resetting coil 2 97. Energi zation of resetting coil 297 causes the arm 294 to return to contact No. 0 in the manner previously described. Movement of arm 294 from contact No. 4 opens the energizing circuit for relay 283 and connects contacts 281 and 282 establishing the previously described energizing circuit for the recycle relay 256 and causing the switching and grinding cycles previously described to be reinitiated. The newly deposited billet will then be ground on four sides in the manner previously described and the cycle of operations will continue as long as there is a billet on the loader rack. It will be noted that, after a new billet is placed on the table 13 and the cycle of operations is resumed causing relay 256 to release after its function has been performed, the arm 1294 of relay 295 moves to contact No. 1 where it remains during the grinding of the first face of thenew billet.

In the event that the loader rack is empty when the ram 120 moves forward, the ram 120 will not deposit a billet on the rails ,98 and 99 and hence will not cause operation of SWlICh1j99. The ram 120 will, however, discharge the ground billet on the conveyor When switch 199 fails to operate after the ram 120 moves forward, reactuation of switch 149 will not complete a circuitfor ,energizat'ion of resetting coil 297 because contacts 369 and 370 are not connected, Accordingly, after the ram 120-returns to its normal or rest position the entire apparatus will remain at rest. Thus, although the grinding wheel will be rotating, neither the table nor the wreciprocable-beam on which'the grinding wheel is mountecl =will-move and the clamping apparatus will remain in 'the-open-position. Therefore, when the supply of billets ion the loadingrac'k is exhausted, the grinding apparatus will remain at rest -,until tfurther billets are placed on the tloading rackrand the manual Eloading switch 280 is actuated. When1the -switch280'is actuated a new billet from the loading-tracktwill :ber-depositedton the ttable 13 causing the cycle of operations previously described as taking place after a billet is loaded to be repeated; The cycle of operations will then continue as described above until the new supply of billets is exhausted.

It will be apparent from the above that the particular switches and relays disclosed are not required for providing the operation of the grinding apparatus as aforesaid, since it will be obvious to those skilled in the art that certain of the functions may be accomplished by other well-known substitutes for such switches and relays. For example, in some cases the functions ofcertain relays may be accomplished by switches and other well-known types of counting apparatus may be substituted for the specific counting apparatus disclosed. Also, it is possible to change the positions of certain of the switches as long as they are operated at the times indicated.

Having thus described my invention with particular reference to the preferred form thereof, it will be obvious to those skilled inthe art to which the invention pertains, after understanding my invention, that various changes and other modifications may be made therein without departing from the spirit and scope of myinvention, as defined by the claims appended hereto.

Whatis claimed as new and desired to be secured by Letters Patent of the United States is 1. Apparatus for grinding the surface of billets compr-isingmeans for reciprocating a billet in a first direction starting from a first position, a grinding whfifil: means for reciprocating said grinding wheel in a second direction transverse to said first direction and starting from a second position and automatic control means operable by said reciprocating means for first causing each of said reciprocating means to execute a cycle of reciprocation and for then stopping both said reciprocating means in said posit-ions thereof.

2 Grinding apparatus comprising a grinding wheel means having a starting position, supporting means for supporting apiece to be ground and'hav-in'g a starting posit-ion, means for moving both said wheel means and said supporting means for thereby producing relative movement between said wheel means and said supporting means, and automatic control means opcnable by at least one of said first-mentioned two means for first causing said moving means to move said grinding wheel means and said supporting means away from and back to said positions and for then stopping said movement when said grinding wheel means and said supporting means have returned to their starting positions.

3. Grinding apparatus comprising a grinding wheel means, supporting means for supporting 'a piece to be ground, means for producing relative movement between said whoel means and said supporting means, first eontro-l means operable by at least one of said first-mentioned two means for stopping said movement when a surface of said piece has been traversed by said. wheel means, turning means operable by said conti ol means for turning said piece a predetermined amount to expose an unground surface to said wheel, second control means eontrolled by said turning means for reinitiating said relative movement after said piece is turned, third control means controlled by one of said turning means and said control means and loading means operable by said third control means for discharging said piece after a predetermined number of the surfaces thereof have been ground and for loading a further piece to be grcnnd on said supporting means, and fourth control means controlled by said loading means for reinitiating said relative movement after said further piece has been loaded on said supporting means.

4. Grinding apparatus comprising a grinding wheel means, supporting means for supportinga piece to be ground, means for producing relative movement between said wheel means and said supporting means, first control means operable by at least one of said first-mentioned two means for stopping said movement wheniansurface .of said piece has been traversed by said wheel means,

turning means operable by said control means for turning said piece a predetermined amount to expose an unground surface to said Wheel, second control means operable by said piece for reinitiating said relative movement after said piece is turned, and third control means operable by one of said control means for preventing further operation of said second control means after a predetermined number of the surfaces of said piece have been ground.

5. Grinding apparatus comprising a grinding wheel means, supporting means for supporting a piece to be ground, means for producing relative movement between said Wheel means and said supporting means, first control means operable by at least one of said first-mentioned two means for stopping said movement when a surface of said piece has been traversed by said Wheel means, turning means operable by said control means for turn ing said piece a predetermined amount to expose an unground surface to said Wheel, second control means operable by said piece for reinitiating said relative movement after said piece is turned, third control means operable by one of said control means for discharging said piece after a predetermined number of the surfaces thereof have been ground and for loading a further piece to be ground on said supporting means, and fourth control means operable by at least one of said second and third control means for reinitiating said relative movement after said further piece has been loaded on said supporting means.

6. Apparatus for grinding the surface of billets com prising a reciprocable table for holding a billet and having thereon means for clamping said billet in grinding position, said clamping means including means for driving said clamping means into and out of engagement with said billet, means for reciprocating said table in a path extending in a predetermined direction, a grinding Wheel mounted adjacent said table and engageable with said billet, means for reciprocating said Wheel in a path extending transversely of the path of said table, first control means for permitting said wheel to engage a face of said billet and for alternatively lifting said Wheel from said face of said billet, second control means operable by said Wheel reciprocating means in a predetermined position thereof for stopping said wheel reciprocating means, third control means operable by said table reciprocating means in a predetermined position thereof for stopping said table, means operable by one of said reciprocating means for operating said wheel control means to its lift position, and means operable by one of said control means for operating said driving means and thereby driving said clamping means out of engagement with said billet.

7. Apparatus for grinding the surface of billets comprising a reciprocable table for holding a billet and having thereon means for turning said billet and means for clamping said billet in grinding position, means for reciprocating said table in a path extending in a predetermined direction, a grinding wheel mounted adjacent said table and engageable with said billet, means for reciprocating said wheel in a path extending transversely of the path of said table, first control means for permitting said wheel to engage a face of said billet and for alternatively lifting said wheel from said face of said billet, second control means operable by said wheel reciprocating means in a predetermined position thereof for stopping said wheel reciprocating means, third control means operable by said table reciprocating means in a predetermined position thereof for stopping said table, means operable by one of said reciprocating means for operating said wheel control means to its lift position, means operable by one of said control means for releasing said clamping means, fourth control means operable by said clamping means in the release position thereof for operating said billet turning means, fifth control means operable by said billet in its turned position for operating said clampmg means and thereby reclamping said billet, and sixth 20 control means operable by said clamping means when said billet is in said grinding position and after it has been reclamped for restarting said table and said Wheel reciprocating means and for releasing said wheel control means and thereby permitting said wheel to engage a face of said billet.

8. Apparatus for grinding the surface of billets comprising a reciprocable table for holding a billet and having thereon means for turning said billet and means for clamping said billet in grinding position, means for reciprocating said table in a path extending in a predetermined direction, a grinding Wheel mounted adjacent said table and engageable with said billet, means for reciprocating said wheel in a path extending transversely of the path of said table, first control means for permitting said Wheel to engage a face of said billet and for alternatively lifting said Wheel from said face of said billet, second control means operable by said wheel reciprocating means in a predetermined position thereof for stopping said wheel reciprocating means, third control means operable by said table reciprocating means in a predetermined position thereof for stopping said table, means operable by one of said reciprocating means for operating said wheel control means to its lift position, means operable by one of said control means for releasing said clamping means, fourth control means operable by said clamping means in the release position thereof for op erating said billet turning means, fifth control means operable by said billet in its turned position for operating said clamping means and thereby reclamping said billet, sixth control means operable by one of said billet and said clamping means after said billet has been reclamped for restarting said table and said wheel reciprocating means and for releasing said first control means and there by permitting said wheel to engage a face of said billet, counting means operable by one of said control means for counting the number of times said last-mentioned control means is operated, seventh control means oper able by said counting means after a predetermined number of operations of said latter means for temporarily suspending further operation of said control and said reciprocating means.

9. Apparatus for grinding the surface of billets comprising a reciprocable table for holding a billet and hav ing thereon means for turning said billet and means for clamping said billet in grinding position, means for re: ciprocating said table in a path extending in a predetermined direction, a grinding wheel mounted adjacent said table and engageable with said billet, means for reciprocating said wheel in a path extending transversely of the path of said table, first control means for per mitting said wheel to engage a face of said billet and for alternatively lifting said Wheel from said face of said billet, second control means operable by said wheel reciprocating means in a predetermined position thereof for stopping said wheel reciprocating means, third con.- trol means operable by said table reciprocating means in a predetermined position thereof for stopping said table, means operable by one of said reciprocating means for operating said wheel control means to its lift position, means operable by one of said control means for releasing said clamping means, fourth control means operable by said clamping means in the release position thereof for operating said billet turning means, fifth control means operable by said billet in its turned position for operating said clamping means and thereby reclamping said billet, sixth control means operable by said billet in said grinding position and after it has been reclamped for restarting said table and said wheel reciprocating means and for releasing said first control means and thereby permitting said wheel to engage a face of said billet, counting means operable by one of said control means for counting the number of times said last-mentioned control means is operable, seventh control means operable by said counting means after a. predetermined 

